Add storage for remote LSKF verification session (342d4d06) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/locksettings/recoverablekeystore/storage/RemoteLockscreenValidationSessionStorage.java

+92 −19

Original line number	Diff line number	Diff line
		@@ -17,9 +17,17 @@
		package com.android.server.locksettings.recoverablekeystore.storage;

		import android.annotation.Nullable;
		import android.os.SystemClock;
		import android.text.format.DateUtils;
		import android.util.Log;
		import android.util.SparseArray;

		import com.android.internal.annotations.VisibleForTesting;
		import com.android.server.locksettings.recoverablekeystore.SecureBox;

		import java.security.KeyPair;
		import java.security.NoSuchAlgorithmException;
		import java.util.ArrayList;

		/**
		* Memory based storage for keyPair used to send encrypted credentials from a remote device.
		@@ -28,8 +36,12 @@ import java.security.KeyPair;
		*/
		public class RemoteLockscreenValidationSessionStorage {

		private final SparseArray<LockScreenVerificationSession> mSessionsByUserId =
		new SparseArray<>();
		private static final long SESSION_TIMEOUT_MILLIS = 10L * DateUtils.MINUTE_IN_MILLIS;
		private static final String TAG = "RemoteLockscreenValidation";

		@VisibleForTesting
		final SparseArray<LockscreenVerificationSession> mSessionsByUserId =
		new SparseArray<>(0);

		/**
		* Returns session for given user or null.
		@@ -40,50 +52,111 @@ public class RemoteLockscreenValidationSessionStorage {
		* @hide
		*/
		@Nullable
		public LockScreenVerificationSession get(int userId) {
		public LockscreenVerificationSession get(int userId) {
		synchronized (mSessionsByUserId) {
		return mSessionsByUserId.get(userId);
		}
		}

		/**
		* Creates a new session to verify lockscreen credentials guess.
		* Creates a new session to verify credentials guess.
		*
		* Session will be automatically removed after 10 minutes of inactivity.
		* @param userId The user id
		*
		* @hide
		*/
		public LockScreenVerificationSession startSession(int userId) {
		public LockscreenVerificationSession startSession(int userId) {
		synchronized (mSessionsByUserId) {
		if (mSessionsByUserId.get(userId) != null) {
		mSessionsByUserId.remove(userId);
		mSessionsByUserId.delete(userId);
		}

		KeyPair newKeyPair;
		try {
		newKeyPair = SecureBox.genKeyPair();
		} catch (NoSuchAlgorithmException e) {
		// impossible
		throw new RuntimeException(e);
		}
		LockScreenVerificationSession newSession = null;
		// TODO(b/254335492): Schedule a task to remove session.
		LockscreenVerificationSession newSession =
		new LockscreenVerificationSession(newKeyPair, SystemClock.elapsedRealtime());
		mSessionsByUserId.put(userId, newSession);
		return newSession;
		}
		}

		/**
		* Deletes session for a user.
		*/
		public void remove(int userId) {
		mSessionsByUserId.remove(userId);
		public void finishSession(int userId) {
		synchronized (mSessionsByUserId) {
		mSessionsByUserId.delete(userId);
		}
		}

		/**
		* Holder for keypair used by remote lock screen validation.
		* Creates a task which deletes expired sessions.
		*/
		public Runnable getLockscreenValidationCleanupTask() {
		return new LockscreenValidationCleanupTask();
		}

		/**
		* Holder for KeyPair used by remote lock screen validation.
		*
		* @hide
		*/
		public static class LockScreenVerificationSession {
		public class LockscreenVerificationSession {
		private final KeyPair mKeyPair;
		private final long mSessionStartTimeMillis;
		private final long mElapsedStartTime;

		/**
		* @hide
		*/
		public LockScreenVerificationSession(KeyPair keyPair, long sessionStartTimeMillis) {
		LockscreenVerificationSession(KeyPair keyPair, long elapsedStartTime) {
		mKeyPair = keyPair;
		mSessionStartTimeMillis = sessionStartTimeMillis;
		mElapsedStartTime = elapsedStartTime;
		}

		/**
		* Returns SecureBox key pair.
		*/
		public KeyPair getKeyPair() {
		return mKeyPair;
		}

		/**
		* Time when the session started.
		*/
		private long getElapsedStartTimeMillis() {
		return mElapsedStartTime;
		}
		}

		private class LockscreenValidationCleanupTask implements Runnable {
		@Override
		public void run() {
		try {
		synchronized (mSessionsByUserId) {
		ArrayList<Integer> keysToRemove = new ArrayList<>();
		for (int i = 0; i < mSessionsByUserId.size(); i++) {
		long now = SystemClock.elapsedRealtime();
		long startTime = mSessionsByUserId.valueAt(i).getElapsedStartTimeMillis();
		if (now - startTime > SESSION_TIMEOUT_MILLIS) {
		int userId = mSessionsByUserId.keyAt(i);
		keysToRemove.add(userId);
		}
		}
		for (Integer userId : keysToRemove) {
		mSessionsByUserId.delete(userId);
		}
		}
		} catch (Exception e) {
		Log.e(TAG, "Unexpected exception thrown during LockscreenValidationCleanupTask", e);
		}
		}

		}

		}

services/tests/servicestests/src/com/android/server/locksettings/recoverablekeystore/storage/RemoteLockscreenValidationSessionStorageTest.java

0 → 100644

+84 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2023 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.server.locksettings.recoverablekeystore.storage;

		import static com.google.common.truth.Truth.assertThat;

		import android.os.SystemClock;

		import androidx.test.filters.SmallTest;
		import androidx.test.runner.AndroidJUnit4;

		import com.android.server.locksettings.recoverablekeystore.SecureBox;

		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;


		@SmallTest
		@RunWith(AndroidJUnit4.class)
		public class RemoteLockscreenValidationSessionStorageTest {
		private static final int USER_ID = 0;
		private static final int USER_ID_2 = 2;

		RemoteLockscreenValidationSessionStorage mStorage;

		@Before
		public void setUp() {
		mStorage = new RemoteLockscreenValidationSessionStorage();
		}

		@Test
		public void get_noStoredSessions_returnsNull() {
		assertThat(mStorage.get(USER_ID)).isNull();
		}

		@Test
		public void startSession() {
		mStorage.startSession(USER_ID);

		assertThat(mStorage.get(USER_ID)).isNotNull();
		assertThat(mStorage.get(USER_ID_2)).isNull();
		}

		@Test
		public void finishSession_removesSessionFromStorage() {
		mStorage.startSession(USER_ID);

		mStorage.finishSession(USER_ID);

		assertThat(mStorage.get(USER_ID)).isNull();
		}

		@Test
		public void getLockscreenValidationCleanupTask() throws Exception {
		long time11MinutesAgo = SystemClock.elapsedRealtime() - 11 * 60 * 1000;
		long time2MinutesAgo = SystemClock.elapsedRealtime() - 2 * 60 * 1000;
		mStorage.mSessionsByUserId.put(
		USER_ID, mStorage.new LockscreenVerificationSession(
		SecureBox.genKeyPair(), time11MinutesAgo));
		mStorage.mSessionsByUserId.put(
		USER_ID_2, mStorage.new LockscreenVerificationSession(
		SecureBox.genKeyPair(), time2MinutesAgo));

		mStorage.getLockscreenValidationCleanupTask().run();

		assertThat(mStorage.get(USER_ID)).isNull();
		assertThat(mStorage.get(USER_ID_2)).isNotNull();
		}
		}